Methods and systems for making reinforced thermoplastic composites, and the products

Abstract

Various methods and systems of making inorganic fiber/flake reinforced composites having a thermoplastic matrix are disclosed. The methods use systems similar to those used to make inorganic fiber/flake reinforced products having a thermoset matrix, but the systems and methods are modified to use thermoplastic precursor monomer(s) followed by in situ polymerization of the monomer(s) during and/or following forming of the desired shape of the products. These methods permit the manufacture of superior inorganic fiber reinforced thermoplastic matrix composites in large and very large shapes heretofore not possible, or practical.

What is claimed is: 
     
       1. A method of making a reinforced thermoplastic composite product comprising:
 forming and attenuating molten glass into glass fibers from a fiberizing bushing; 
 coating the glass fibers with an aqueous sizing composition to form sized glass fibers; 
 drying the sized glass fibers to form dried glass fibers; 
 preparing a resin mixture containing one or more thermoplastic precursor monomers and one or more catalyst compounds; 
 heating at least one of the dried glass fibers or the resin mixture, wherein:
 heating the dried glass fibers comprises heating the dried glass fibers to a temperature of at least about 100 degrees C., or 
 heating the resin mixture comprises heating the mixture to a temperature of at least about 100 degrees C.; 
 
 impregnating the dried glass fibers with the resin mixture to form an amalgam of glass fibers and resin mixture prior to contacting a mold element followed by bringing the impregnated glass fibers into contact with the mold element, or alternatively impregnating the dried glass fibers with the resin mixture while the resin mixture is in the mold element, to form a desired shape of impregnated glass fibers, and 
 heating the amalgam to a temperature in a range of about 140 to about 190 degrees C. until at least about 90 percent of the monomer(s) have polymerized to one or more thermoplastic polymers. 
 
     
     
       2. The method of  claim 1 , wherein the aqueous sizing composition comprises one or more activator compounds. 
     
     
       3. The method of  claim 2 , wherein the one or more activator compounds comprise N-propylsilyl-N′-acyl-ureas. 
     
     
       4. The method of  claim 2 , wherein the one or more activator compounds comprise 2-oxo-N-(3-(triethoxysilyl)propyl)azepane-1-carboxamide. 
     
     
       5. The method of  claim 1 , wherein the resin mixture further contains one or more activator compounds that will react with the monomer(s)/catalyst(s) to cause polymerization. 
     
     
       6. The method of  claim 1 , further comprising heating a mold element to a temperature in the range of about 130 to about 200 degrees C. prior to impregnating the dried glass fibers with the resin mixture. 
     
     
       7. The method of  claim 1 , wherein both the dried glass fibers and the resin mixture are heated to a temperature above about 100 degrees C. prior to impregnating the dried glass fibers with the resin mixture. 
     
     
       8. The method of  claim 1 , wherein the resin mixture also comprises one or more materials selected from a group consisting of a filler, a pigment, and a colorant. 
     
     
       9. The method of  claim 1 , wherein the monomers comprise a lactam or lactone having from 3 to 12 carbon atoms in the main ring. 
     
     
       10. The method of  claim 1 , wherein the monomers comprise caprolactam or caprolactone. 
     
     
       11. The method of  claim 1 , wherein the one or more catalyst compounds comprise an alkali metal salt of the monomer. 
     
     
       12. The method of  claim 1 , wherein the one or more catalyst compounds comprise sodium caprolactam. 
     
     
       13. The method of  claim 1 , wherein the resin mixture comprises no activator compounds. 
     
     
       14. A method of making a reinforced thermoplastic composite product comprising:
 forming and attenuating molten glass into glass fibers from a fiberizing bushing; 
 coating the glass fibers with an aqueous sizing composition comprising one or more activator compounds to form sized glass fibers; 
 drying the sized glass fibers to form dried glass fibers; 
 preparing a resin mixture containing one or more thermoplastic precursor monomers and one or more catalyst compounds, the catalyst compound(s) causing polymerization of the monomer(s) when brought into contact with the dried glass fibers, the one or more activator compounds being materials that will react with the one or more thermoplastic precursor monomers to cause polymerization of the monomers in a temperature range of about 140 to about 200 degrees C. to produce a thermoplastic matrix around glass fibers, 
 heating at least one of the dried glass fibers or the resin mixture, wherein:
 heating the dried glass fibers comprises heating the dried glass fibers to a temperature of at least about 100 degrees C., or 
 heating the resin mixture comprises heating the resin mixture to a temperature of at least about 100 degrees C.; 
 
 impregnating the dried glass fibers with the resin mixture to form an amalgam of glass fibers and resin mixture prior to contacting a mold element followed by bringing the impregnated glass fibers into contact with the mold element, or alternatively impregnating the dried glass fibers with the resin mixture while the resin mixture is in the mold element, to form a desired shape of impregnated glass fibers, and 
 heating the amalgam to a temperature in a range of about 140 to about 190 degrees C. until at least about 90 percent of the monomer(s) have polymerized to one or more thermoplastic polymers. 
 
     
     
       15. The method of  claim 14 , further comprising heating a mold element to a temperature in the range of about 130 to about 200 degrees C. prior to impregnating the dried glass fibers with the resin mixture. 
     
     
       16. The method of  claim 14 , wherein both the dried glass fibers and the resin mixture are heated to a temperature above about 100 degrees C. prior to impregnating the dried glass fibers with the resin mixture. 
     
     
       17. The method of  claim 14 , wherein the monomers comprise a lactam or lactone having from 3 to 12 carbon atoms in the main ring. 
     
     
       18. The method of  claim 14 , wherein the monomers comprise caprolactam or caprolactone. 
     
     
       19. The method of  claim 14 , wherein the one or more catalyst compounds comprise an alkali metal salt of the monomer. 
     
     
       20. The method of  claim 14 , wherein the resin mixture comprises no activator compounds.